Merge ~ltrager/maas:lp1881821_2.7 into maas:2.7

[Lee Trager]

Backport of b7b7167 LP: #1881821 - Allow link speed to exceed interface speed.

[Lee Trager (ltrager)]

review: Approve

diff --git a/src/maasserver/models/interface.py b/src/maasserver/models/interface.py
index ceb3a8b..312e939 100644
--- a/src/maasserver/models/interface.py
+++ b/src/maasserver/models/interface.py
@@ -1632,11 +1632,6 @@ class Interface(CleanSave, TimestampedModel):
         }
 
     def save(self, *args, **kwargs):
-        if (
-            self.link_speed > self.interface_speed
-            and self.interface_speed != 0
-        ):
-            raise ValidationError("link_speed may not exceed interface_speed")
         if not self.link_connected:
             self.link_speed = 0
         return super().save(*args, **kwargs)
diff --git a/src/maasserver/models/tests/test_interface.py b/src/maasserver/models/tests/test_interface.py
index 62d70ab..6b215ae 100644
--- a/src/maasserver/models/tests/test_interface.py
+++ b/src/maasserver/models/tests/test_interface.py
@@ -1338,11 +1338,15 @@ class InterfaceTest(MAASServerTestCase):
         #: Test is this doesn't raise an exception
         interface.remove_tag(tag)
 
-    def test_save_link_speed_may_not_exceed_interface_speed(self):
+    def test_save_link_speed_may_exceed_interface_speed(self):
+        # LP:1877158 - Interfaces which use aggregate physical links do
+        # not report the full max interface speed.
         interface = factory.make_Interface(INTERFACE_TYPE.PHYSICAL)
         interface.interface_speed = 100
         interface.link_speed = 1000
-        self.assertRaises(ValidationError, interface.save)
+        interface.save()
+        self.assertEquals(100, interface.interface_speed)
+        self.assertEquals(1000, interface.link_speed)
 
     def test_save_link_speed_may_exceed_unknown_interface_speed(self):
         interface = factory.make_Interface(INTERFACE_TYPE.PHYSICAL)